<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
<div class="box">
    <div class="selected">1</div>
    <p>2</p>
</div>
<ul>
    <li>1</li>
    <li>2</li>
    <li>3</li>
    <li>4</li>
    <li>5</li>
    <li>6</li>
    <li>7</li>
    <li>8</li>
    <li>9</li>
    <li>10</li>
</ul>
<script src="js/jquery-3.6.0.min.js"></script>
<script>
$(function(){
    $('div').filter('.selected').css('background','red');
    //$('ul li').slice(0,5).css('background','yellow');
    $('ul li').slice(2,6).css('background','yellow');

})
</script>
</body>
</html>